Stem Cells Could Help Heal Broken Hearts

Even after recovery, heart attacks can leave a lasting mark on your ticker -- scar tissue weakens the muscle and prevents it from functioning as well as it did before seizing up. A pioneering stem-cell procedure, however, could cut the damage in half.

According to the results of a small safety trial by the Cedars-Sinai Heart Institute, published in the Lancet medical journal, introducing stem cells derived from the patient's own heart have shown an "unprecedented" ability to reduce scarring as well as regenerate healthy cardiac tissue.

During a heart attack, the organ is deprived of oxygen and its tissue begins to die off. As the heart heals from the attack, any damaged muscle is replaced by scar tissue, which prevents the heart from beating properly and pumping the requisite blood flow the body needs.

The CADUCEUS (CArdiosphere-Derived aUtologous stem CElls to Reverse ventricUlar dySfunction) study involved 25 patients -- eight serving as the control group, the other 17 actually receiving the treatment. Researchers first performed extensive imaging scans to identify location and severity of scarring, then biopsied a half-raisin-sized piece the patient's heart tissue. Doctors then isolated and cultured stem cells from it and injected the lab-grown stem cells -- roughly 12-25 million of them -- back into the heart.

After a year, scarring in patients that received the treatment decreased by an astounding 50 per cent while the control group showed no decrease in scarring. "These results signal an approaching paradigm shift in the care of heart attack patients," said Shlomo Melmed, dean of the Cedars-Sinai medical faculty. The scars were once believed to be permanent but this technique shows promise as a means to regenerate the damaged muscle. It should be noted however, that the heart's ability to pump did not increase as the scar tissue disappeared.

"While the primary goal of our study was to verify safety, we also looked for evidence that the treatment might dissolve scar and regrow lost heart muscle," Eduardo Marbán, director of the Cedars-Sinai Heart Institute, told PhysOrg. "This has never been accomplished before, despite a decade of cell therapy trials for patients with heart attacks. Now we have done it. The effects are substantial, and surprisingly larger in humans than they were in animal tests."